Surprising glacial and nearly ice-free periods in last 66 million years
Rutgers University
New research by Rutgers scientists reaffirms that modern sea-level rise is linked to human activities and not to changes in Earth’s orbit.
Surprisingly, the Earth had nearly ice-free conditions with carbon dioxide levels not much higher than today and had glacial periods in times previously believed to be ice-free over the last 66 million years, according to a paper published in the journal Science Advances.
“Our team showed that the Earth’s history of glaciation was more complex than previously thought,” said lead author Kenneth G. Miller, a Distinguished Professor in the Department of Earth and Planetary Sciences in the School of Arts and Sciences at Rutgers University-New Brunswick. “Although carbon dioxide levels had an important influence on ice-free periods, minor variations in the Earth’s orbit were the dominant factor in terms of ice volume and sea-level changes – until modern times.”
Sea-level rise, which has accelerated in recent decades, threatens to permanently inundate densely populated coastal cities and communities, other low-lying lands and costly infrastructure by 2100. It also poses a grave threat to many ecosystems and economies.
The paper reconstructed the history of sea levels and glaciation since the age of the dinosaurs ended. Scientists compared estimates of the global average sea level, based on deep-sea geochemistry data, with continental margin records. Continental margins, which include the relatively shallow ocean waters over a continental shelf, can extend hundreds of miles from the coast.
The study showed that periods of nearly ice-free conditions, such as 17 million to 13 million years ago, occurred when the concentration of atmospheric carbon dioxide – a key greenhouse gas driving climate change – was not much higher than today. However, glacial periods occurred when the Earth was previously thought to be ice-free, such as from 48 million to 34 million years ago.
“We demonstrate that although atmospheric carbon dioxide had an important influence on ice-free periods on Earth, ice volume and sea-level changes prior to human influences were linked primarily to minor variations in the Earth’s orbit and distance from the sun,” Miller said.
The largest sea-level decline took place during the last glacial period about 20,000 years ago, when the water level dropped by about 400 feet. That was followed by a foot per decade rise in sea level – a rapid pace that slowed from 10,000 to 2,000 years ago. Sea-level rise was then at a standstill until around 1900, when rates began rising as human activities began influencing the climate.
Future work reconstructing the history of sea-level changes before 48 million years ago is needed to determine the times when the Earth was entirely ice-free, the role of atmospheric carbon dioxide in glaciation and the cause of the natural fall in atmospheric carbon dioxide before humans.
Rutgers coauthors include Professor James V. Browning, doctoral student W. John Schmelz and professors Robert E. Kopp, Gregory S. Mountain and James D. Wright, the senior author of the study.
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OKaay! They searched and researched until they got the desired conclusion. enough already! No more research.
Rutgers research affirms sea level rise and affirms CO2 harmful warming and affirms ocean acidification and affirms that while-biosphere-did-just-fine-with-10,000ppm-CO2-a-rise-of-400-to-500-will-kill-all-life-yes-I’m-a-m0r0n is for a simple reason – Rutgers research need money. End of story.
I stopped at acceleration.
https://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?plot=50yr&id=680-140
I have yet to see ANY evidence of acceleration in sea level rise. It annoys me the way people just drop this phrase into articles without proof or attribution. Is there some evidence of acceleration that I am perhaps unaware of?
Usually they show acceleration of sea level rise by splicing together the tide gauge data with the satellite data starting in 1993. Satellite gives a larger number so it looks like acceleration. It’s fraud of course. Don’t know if that is what was done here
We here in Australia unfortunately receive world news late.
Two questions:
1. Was the pic of the Statue of Liberty taken yesterday morning or yesterday afternoon? AND
2. Was it high or low tide when the pic was taken?
Excellent questions. Like Einstein said, “Don’t listen to the person who has the answers; listen to the person who has the questions.”
Did Obama make his recent coastal purchase,based on Rutgers continued flogging of the “we’re all going to drown theme”. Seems a little like a scam to me. How far above sea level is Rutgers.Are they making plans to move to higher ground.Or!!!
From the paper with 101 references, influencing journal impact factors no doubt.
“Amplitudes of sea-level change
The estimates provided here from scaling of deep-sea δ18Obenthic and backstripping have large errors (±10 to ±20 m; see Materials and Methods). Given this, the agreement shown between the two estimates (Fig. 1D) is remarkable (see Materials and Methods for statistical comparisons of the two records)……..Last, to estimate the effect of the distribution of potential parameter values and temporal uncertainties on f(t), we apply a random sampling/Monte Carlo method that alters the hyperparameter values and ages of the input data drawing from their probability distributions.”
Are hyperparameters related to hyperneuroses? What year did “large errors” become insignificant?
Some smart people will always look upon correlation as evidence of causation. I call them “wise fools.”
Correlation is a reason to examine the possibility of causation.
And if they can’t find it, they’ll make it up, apparently.
You sir, are obviously well trained in the art of climate science.
Correlation is not causation. However it’s often a good clue as to where to start looking for causation.
Correlation has no direction; causation does. The first question you have to consider when trying to go from correlation to causation is what causes what. Almost no consideration has been given to the notion that warming since the little ice age has caused CO2 levels to increase. It is assumed that causation runs entirely in the opposite direction. An obvious physical mechanism and much evidence to the contrary is ignored.
It’s not changes in the orbit, therefore it must be caused by man.
Is there any logical fail that these guys won’t use to advance their cause?
@Article
“The largest sea-level decline took place during the last glacial period about 20,000 years ago, when the water level dropped by about 400 feet. That was followed by a foot per decade rise in sea level – a rapid pace that slowed from 10,000 to 2,000 years ago. Sea-level rise was then at a standstill until around 1900, when rates began rising as human activities began influencing the climate.”
Yes, sea levels have risen since the last Ice Age. But was it it a monotonic rise, as strongly implied by the bold text above?
If so, why are so many ancient Roman and medieval seaports ‘high and dry inland’ today? For example, Burgh and Harlech castles, which once stood at the edge of the sea, are now a mile or so inland, in spite of considerable subsidence of the land over the centuries?
They can’t possibly know what CO2 and sea levels were over the last 66 million years, much less the cause of sea level variations. Re sea level, consider how much tectonic activity there has been. The Atlantic Ocean is only about 180 million years old.
La La Land